Plate stack heat exchanger



Oct. 8, 1940. 'r. K. E. KALLSTENIUS PLATE STACK HEAT EXCHANGER 2 Sheets-Sheet 1 Filed Nov. 126, 1938 Oct. 1940. 'r. K. E. KALLSTENIUS 2,217,315

PLATE STA-CK HEAT EXCHANGEB Filed Nov. 2 6, 1938 2 Sheets-Sheet 2 FIG. 2a.

FIG. 5.

INVENTOR.

Patented Oct. 8, 1940 UNITED STATES PATENT OFFICE PLATE s'mcx HEAT EXCHANGER Application November 26, 1938, Serial No. 242,457 In Sweden November 30, 1937 4 Claims.

My invention relates to fluid heat exchangers and more particularly to exchangers of the spiral flow type.

In accordance with my invention I provide a heat exchanger of this kind made up of a plurality of similar sections secured together so that the fluids may flow through the different .sections either in series or in parallel. One of the advantages of my improved heat exchanger is that its capacity may be varied by adding or subtracting sections. Inasmuch as the sections may be arranged for parallel flow, an addition of sections increases the volume of fluid which may be handled by the heat exchanger, as well as increasing the heat transfer area.

One of the objects of my invention is to provide, in a heat exchanger of this type, spiral channels having a substantially rectangular cross-section. Such cross-section not only makes 20 possible a maximum heat transfer area, but also gives a substantially constant velocity of flow of the fluids, thereby reducing the tendency for any solids to be precipitated. l

' Another object of my invention is to utilize the 25 crests of the channels in one section for closing the opened edges of the channels in an adjacent section. In accordance with one embodiment of my invention different fluids are caused to flow in corresponding channels in adjacent sections, whereby heat is transferred through these closures at the edges of the grooves, as well as through the spiral walls between the different grooves in each section.

Further objects and advantages of my inven- 35 tion will be apparent from the following description considered in connection with the accompanying drawings, which form a part of this specification and of which:

Fig. l is a cross-sectional view of one embodi- 40 ment of my invention and is taken on the line II of Fig. 2;

Fig. 2 is a cross-sectional view taken on the line IIII of Fig. 1;

Fig. 2a is a top view of an element forming part of the heat exchanger illustrated in Fig. 1;

Fig. 3 is a cross-sectional view of another embodiment of my invention, and is taken on the lines III-III of Figs. 4 and 5;

Fig. 4 is a cross-sectional view taken on the line IV-IV of Fig. 3; and

Fig. 5 is a cross-sectional view taken on the line V-V of Fig. 3.

Referring more particularly to Figs. 1, 2 and 2a, reference characters I and la designate gen- 55 erally the plate sections of which the heat exchanger is made up. Each section I includes spiral walls In which are alternately connected together at their top and bottom edges by radial walls 4. The walls 4 and Ill thus define a pair of spiral channels 2 and 3, the walls 4 constituting crests of the grooves forming these channels. As will be seen, the channels in each plate are open atone edge, but these open edges are closed by the walls 4 in adjacent plates, with the exception of the channels formed in the end sections, which are closed by headers 6 and 6'.

Each plate section is also formed to provide inlet manifolds 20 and 30 and outlet manifolds 22- and 33. The spiral channel 2 of each section is connected at one end to an inlet manifold 20 and at the opposite end to outlet manifold 22, while the spiral channel 3 is connected at one end to inlet manifold 30 and at the other end to outlet manifold 33.

Section la is the same as sections I, except that it is provided with a radial wall 4d which closes one end of inlet manifold 30 and outlet manifold 22. Header 6 is provided with an inlet manifold 30 and an outlet manifold 22, while 6' is formed with an inlet manifold 20 and an outlet manifold 33.

Any suitable packing means, such as is designated by 5a may be provided for preventing tie-bolts H which extend through flanges l2 formed on the headers.

The operation of the above described heat ex-' changer is as fOllOWSE Fluid entering manifold in header 6 flows into header 30 in section la and thence through spiral channel ,3 to manifold 33 in this section. Inasmuch as this manifold is in direct communication with manifold 33 in plate section I immediately therebelow, the fluid flows into this manifold and through spiral channel 3 to manifold 30. Gasket 5b prevents the flow of fluid from the'manifold 33 directly above the gasket to the similar manifold formed in the section immediately below the gasket. However, the

2 Y. aamare opening a in the gasket permits flow of fluid from the manifold 30 in the section immediately above the gasket to the similar manifold in the section below the gasket. Inasmuch as this manifold is in direct communication with manifold 30 in the lowermost section, the fluid flows in parallel through the channels 3 in the two lower sections and into the manifolds 33 in each of these sections. From here-it is discharged through the manifold 33 in the lower header 6'.

The other fluid is admitted through the manifold 20 in header 6' and flows into the manifolds 26 in'the two lower sections, inasmuch as all of these manifolds are in direct communication. The fluid flows in parallel through the spiral channels 2- in the two lower sections, and into the manifolds 22. From here the fluid flows through the opening 22a in the gasket 5b and thence through the spiral channel 2 in the section immediately above the gasket. From this channel the fluid is discharged .into the maul- 1 fold 26,, which is in direct communication with the corresponding manifold in section la, from where the fluid flows through channel 2 to the manifold 22 in section la, and thence out through the manifold 22 in header 6.

Thus it will be seen that the flow of both fluids is in series through the two uppermost sections, and in parallel through the two lowermost sections. It will be noted that the fluid which is admitted through manifold 30 in header 6 always flows through a spiral channel 3 in each of the sections, while the fluid admitted through manifold 26 in header 6' always flows through the spiral channel 2. Thus, inasmuch as the same fluid is flowing in corresponding channels in the different sections, little or no heat transfer takes place through the walls 4 forming the crests.

In the embodiment illustrated in Figs. 3 through 5, the arrangement is such that dissimilar fluids flow through the corresponding channels in adjacent plate sections, and therefore the walls forming the crests, as well as the spiral walls serve to transfer heat. In this embodiment the heat exchanger is made up of a plurality of plate sections lb and lo arrangedalternately. In Fig. 4 there is shown a cross-section taken through a plate lb while Fig. 5 shows a cross-section taken through a plate l0. Each plate is arranged to provide manifolds i5, l6, l1 and I8. As appears in Fig. 4 manifold l6 of sectionlb is connectedthrough an opening 25. with a channel 26. The opposite end of this channel communicates with manifold ll. ,Manifold I6 is connected to a channel 2f, the opposite end of which is connectedto manifoldlt. In plate section lc, on theother hand, as appears from Fig. 5, manifold I5 is connected through an opening 28 with channel .21, while the other end of this channel is connected through an opening 29 with manifold H. The other channel 26 communicates at or? end with manifold l6, while at. the opposite end it is connected through an opening 34 with mani fold l8.

In plate lb manifold I5 is opened at both ends, while in plate lc this manifold is closed at the upper end by means of a radial wall 40. Manifold l6 in plate la is formed with an opening 35 in its lower wall, as is shown in Fig. 4, but in plate section lcthere is no corresponding opening, as appears from Fig. 5. Manifold l! in section lb is closed at the top by a solid wall, while manifold IT in section lchas an opening 36 in its upper wall. Manifold l8 in section lb has a solid bottom wall, while the manifold in section lc has an opening 31 formed in its bottom wall.

The flow of fluids through the above described heat exchanger is as follows:

Fluid admitted through the open upper end of manifold IS in plate section .lb flows therefrom through opening 25 into channel 26. The fluid flows from the opposite end of this channel into manifold l1 and thence through the opening 36 into the corresponding manifold II in plate section lc. Fromthis manifold the fluid flows through opening 29 into channel 21 and from this channel through the opening 28 to manifold l5. the fluid has passed through channel 26 in section lb, but in channel 21 in the section lc. Fluid which is admitted into manifold l8 in section lb flows therefrom through passage 21 in this section to manifold l6. From this manifold it flows through opening 35 into the corresponding manifold in section lc and thence into channel 26 in this section and through opening 31 into manifold l8. Consequently, this fluid has passed through channel 21 in section lb, but through channel 26 in section lc. Consequently, different fluidsv flow through corresponding channels in adjacent plates and therefore an exchange of heat takes place through the walls forming the crests of the channels and which separate corresponding channels in the adjacent plates. In this manner, the entire metal wall area of the sections forming the heat exchanger is utilized for heat transfer.

While I have shown and described two more or less specific embodiments of my invention, it

is to be understood that this has been done for the purpose of illustration only, and the scope of my invention is not to be limited thereby but is to be determined from the appended claims.

I claim:

1. A heat exchange apparatus comprising plates with convolute flow channels of a substantially rectangular cross-section formed by grooves in opposite faces of each plate so as to present facial crests between grooves on both one intermediate plate have the open sides thereof closed by the abutting crests of adjacent plates and means for connecting the ends of successive channels of adjacent plates.

2. A heat exchange apparatus comprising plates with con'volute flow channels of a substantially rectangular cross-section formed by grooves in opposite faces of each plate so as to present facial crests between grooves on both sides, said plates being assembled face to face in abutting position so that the channels of any one intermediate plate have the open sides thereof closed by the abutting crests of adjacent plates, and means for connecting the respective channels of adjacent plates so that the channels which are connected together are radially out of alignment.

3. A heat exchanger apparatus comprising plates with convolute flow channels of a substantially rectangular 'corss-section formed by outer open ended chambers formed in each plate,

each channel being connected at one end to an outer chamber and at the other end to an inner chamber, corresponding chambers in the different plates being in alignment and in communication with each other to form manifolds, whereby corresponding channels in the difierent plates are connected for parallel flow therethrough.

4. A heat exchange apparatus comprising plates with convolute. flow channels of a substantially rectangular cross-section formed by grooves in opposite faces of each plate so as to present facial crests between grooves on both sides, said plates being assembled face to face in abutting position so that the channels of any one intermediate plate have the open sides thereof closed by the abutting crests of adjacent plates, and means for connecting the channels of adjacent plates comprising a pair of inner chambers and a pair of outer chambers, each channel being connected at one end to an inner chamber and at the other end to an outer chamber, the chambers in any plate being directly in communication with corresponding chambers in and communicating chambers being connected to non-corresponding channels in adjacent plates,

whereby the connected channels in adjacent plates are r'adially out of alignment.

TORSTEN KARL EDMUND KALLSTENIUS. 

